DE3820065A1 - METHOD FOR PRODUCING PVC HARD FILMS - Google Patents

Description

The invention relates to a method for producing PVC hard films using the low-temperature process Processing of an emulsion PVC mass with K values from 70 to 80 using calender and smelting rollers.

The low-temperature process, also called Luvitherm process, is a well-known technology for the production of PVC hard films, this in detail in Becker / Braun, plastic manual vol. 2/2, p. 1006-1007, Carl Hanser-Verlag Munich (1986). It works with emulsion PVC types with K values from 70 to 80 and allows the production of both stretched films that especially used as adhesive tapes, as well unstretched foils, for example deep-drawn in a cup shape and as packaging containers, especially for Margari ne, are used. Such films are often be prints, instead of the usual, solvent-based Printing inks for work physiological reasons recently water-based inks are preferred.

The above for the production of PVC hard films contain the type of emulsion PVC used production-related emulsifiers in the order of approx. 2% by weight. For the production of PVC hard films Lubricant up to 6 parts by weight per 100 parts by weight of resin (phr) required. Derivatives of  Montanic acid, especially full esters of ethylene glycol or of butane-1,3-diol, used because only such waxes required compatibility in the matrix PVC / emulsifier exhibit. However, the montanic acid esters mentioned also have Limits regarding their compatibility in PVC. Moreover they already work with a dosage of 3.5 to 5 phr already hydrophobic, so that the printability of PVC hard films with water-based printing inks is impaired.

The method of the invention is based on the production of water-based printing inks printable PVC hard foils aimed at using special lubricants come, even with additional quantities in the order of 6 Parts by weight with the emulsifiers contained in the emulsion PVC are tolerated.

This object is achieved in that the Emulsion PVC mass effective amounts of partial esters Montanic acid and polyalcohols with 2 to 12, especially 3 to 12 carbon atoms, and 2 to 6, in particular 3 to 6 Adds hydroxyl groups, the partial esters in the molecule have at least one free hydroxyl group and that Number ratio of the free hydroxyl groups to Montanoyl groups is between 5: 1 and 1: 3.

Typical examples of polyalcohols with 3 to 12 carbon atoms and 3 to 6 hydroxyl groups to form the Partial esters of montanic acid to be used according to the invention are glycerin, diglycerin, triglycerin and tetraglycerin finally isomers thereof, trimethylolpropane, Di trimethylolpropane, pentaerythritol, dipentaerythritol, mannitol and Sorbitol and sorbitan.

Preferred representatives of the Par tialesters are glycerol monomontanate, glycerol dimontanate, Diglycerin monomontanate, triglycerin monomontanate, Tetraglycerol monomontanate, pentaerythritol monomontanate,  Dipentaerythritol monomontanate and sorbitan monomontanate. These Partial esters can be obtained by using montanic acid the corresponding polyalcohols in the presence of customary acid Catalysts, e.g. Toluenesulfonic acid, metallic tin, Tin (II) oxide, acidic titanium compounds or the like, in the stoichiometric corresponding to the desired end products Conditions. The skilled worker is familiar with that such reactions are not exclusively the desired ones Partial ester is obtained, but always a mixture that predominantly contains the desired partial ester. About that In addition, it is also possible to selectively mix partial esters to manufacture, e.g. one mole of polyalcohol statistically with 1.5 mol montanic acid to so-called sesquimontanates responds. Typical example of such Partial ester mixtures are glycerin-1,5-montanat or Pentaerythritol-1,8-montanate.

According to a further advantageous embodiment of the invention the partial esters are used in amounts of 0.5 to 7, especially 2 to 6 parts by weight per 100 parts by weight Emulsion PVC too.

It is further preferred that the emulsion PVC composition is effective Amounts of common tin stabilizers, e.g. Butyl tin mercaptopropionate or organic sulfur-containing stabilizers sensors, e.g. Diphenylthiourea to add.

In addition, small amounts of fillers, for example titanium dioxide, can be added to the emulsion PVC compositions if these are to be processed into unstretched films.

The invention is based on preferred from management examples explained in more detail.

Production of partial esters to be used according to the invention

• a) Glycerol dimontanate
  A three-necked flask equipped with a stirrer, thermometer and descending the Liebig condenser was charged with 19 g glycerol (0.207 mol), 165 g montanic acid (0.413 mol; Hoechst-Wachs S) and 0.4 g tin dust. The mixture was heated to 210 ° C. with stirring, a slight vacuum being applied, which was increased to 20 mbar within 1.5 h. After this time the acid number had dropped to approximately 1. The mixture was cooled to 100 ° C, bleached and filtered. A light yellow hard wax with a dropping point of 79 ° C. was obtained.
• b) glycerol monomontanate
  Analogously to a), 400 g of montanic acid (Hoechst-Wachs S), 97 g of glycerol (5% excess) and 0.5 g of tin dust were converted. A brownish-yellow hard wax with a dropping point of 84.2 ° C. was obtained.
• c) Diglycerol sesquimontanate
  Analogously to a), 112 g of diglycerin (0.67 mol), 400 g of montanic acid (1.0 mol) and 0.4 g of tin dust were heated to 200 ° C., a slight vacuum being applied. This was increased to 24 mbar within 3.5 hours. The product had an acid number of approximately 1. After cooling to 100 ° C, bleaching and filtering, a brown-colored hard wax with a dropping point of 81 ° C was obtained.
• d) pentaerythritol dimontanate
  Analogously to a), 28.1 g of pentaerythritol (0.207 mol), 165 g of montanic acid (0.413 mol) and 0.4 g of tin dust were heated to 200 ° C., a slight vacuum being applied. After 2 h, 20 mbar had been reached; the acid number was approximately 1. After cooling to 100 ° C., bleaching and filtering, a brownish yellow hard wax with a dropping point of 79 ° C. was obtained.

Analogous to the way described in a)

• e) pentaerythritol-1,8-montanate,
• f) pentaerythritol-2,5-montanate,
• g) sorbitan dimontanate,
• h) diglycerol monomontanate,
• i) Diglycerol trimontanate
• j) Tetraglycerin monomontanate
• k) tetraglycerol trimontanate,
• l) iso-tetraglycerol monomontanate,
• m) Glycerol 1,4-monomontanate

receive.

Examples 1 to 26

A basic mixture of 100 parts by weight of a commercially available Emulsion PVC (K = 78) and 0.5 part by weight of butyl tin mercaptopropionate were different amounts different Partial esters added; those added in detail  Partial esters and the amounts of these result from the following table.

The plasticizing behavior of the molding compositions obtained was included Help from a plastograph (Plasticorder PL 151; Brabender; see P. Klenk, "The plastic processor", 21st year, 1970/7, Pp. 642-644) checked. The chamber temperature was 165 ° C Speed 30 U / min. The tests were each 33 g Substance executed.

As a comparison substances were a commercially available Ethylene glycol dimontanate (Hoechst-Wachs®E) and a partial ver Soaped calcium-containing butylene glycol dimontanate (high Wachs®OP) tested.

The results found can be seen in FIG. 1, which shows the torque curves determined. It can be seen that the PVC molding compositions obtained according to the invention have a similar plasticizing behavior to the comparative compositions and are therefore suitable as lubricants for rigid PVC films.

For determining the printability with water-based Printing inks were firstly subjected to the contact angle test according to Dipl.-Ing. Opkircher and on the other hand the ink test based on DIN 53364 used. For the test according to Dipl.-Ing. Opkircher were different from the above PVC molding compounds produced films with a drop of distilled water offset; then the contact angle between the film and Drops determined. The smaller the determined contact angle, the better the wettability of the film surface with the test ink.

The assessment of the ink test according to DIN 53364 was carried out according to a grading scale from 1 (easily wettable) to 5 (not wettable bar).  

The results obtained in the above tests are summarized in the table below, the further shows the results for comparison formulations, namely for films made without the addition of a lubricant (comparison A) and for films with different amounts of added Ethylene glycol dimontanate (comparison B to D).

It turns out that the added according to the prior art Ethylene glycol dimontanate has a hydrophobic effect; give against the invention with partial montanates as a lubricant produced films an improved wettability, the often even the one without any added lubricant manufactured foils surpasses.  

table

Manufactured PVC hard films

Basic approach: 100 parts by weight of E-PVC (K = 78), 0.5 parts by weight of butyltin mercaptopropionate

Claims (5)

1. A process for the production of hard PVC films by the low-temperature process by processing an emulsion PVC mass with K values of 70 to 80 by means of calender and melting rollers, characterized in that the emulsion PVC mass is effective Amounts of partial esters from montanic acid and polyalcohols with 2 to 12 carbon atoms and 2 to 6 hydroxyl groups are added, the partial esters in the molecule having at least one free hydroxyl group and the number ratio of the free hydroxyl groups to montanoyl groups being between 5: 1 and 1: 3. 2. The method according to claim 1, characterized in that one Partial esters of montanic acid and 3 to 12 carbon atoms and 3 to 6 hydroxyl-containing polyalcohols used. 3. The method according to claim 1 or 2, characterized in that the partial esters from that of glycerol monomontanate, Glycerol dimontanate, diglycerol monomontanate, Diglycerin trimontanate, triglycerin monomontanate, Tetraglycerin monomontanate, tetraglycerin trimontanate, Pentaerythritol monomontanate, dipentaerythritol monomontanate  and sorbitan monomontanate formed group selected are. 4. The method according to at least one of claims 1 to 3, characterized in that the partial esters in quantities from 0.5 to 7, in particular 2 to 6 parts by weight per 100 Parts by weight of emulsion PVC are added. 5. The method according to at least one of claims 1 to 4, characterized in that the emulsion PVC mass effective amounts of conventional tin stabilizers or orga added sulfur-containing stabilizers.